1. Field of the Invention
The present invention relates to an apparatus for manufacturing pouches made of webbed plastic, foil or film, and more particularly, to an apparatus for forming, filling and sealing such pouches at a continuous rate.
2. Description of the Prior Art
Webbed pouches (also sometimes referred to as packets or sachets) are commonly used within many industries to package and distribute individual portions of liquids or viscous materials, such as foods, beverages, condiments, pharmaceutical or personal care products, and chemicals. Such pouches are also used to package and distribute other objects or commodities, such as candy, nuts, salt, pepper, and the like. The widespread popularity of such pouches, and their ease of distribution, has led in a heightened interest in machines and methods for forming, filling and sealing such pouches.
The traditional apparatus for manufacturing webbed pouches comprises two rolls for dispensing sheets of webbed film, foil or plastic of equal dimensions, a plurality of sealing devices appropriate for such film, and means for inserting the contents into the film pouches. The apparatus first receives film from the dispensers, and aligns their respective edges. The sealing devices are then applied to all but one of the edges, forming a pouch with a cavity and opening. The contents (liquids, viscous materials or other substances) are inserted into the cavity through the opening. The opening is then sealed and separated from the film. The process is then repeated.
However, such a traditional apparatus is generally unsuitable for manufacturing large volumes of film pouches at very high speeds. Specifically, the traditional process necessitates a certain delay or pause in the flow of film through the machine, since the machines must stop during every cycle while the side and/or leading and trailing edges of the pouches are pressed and sealed, and when rows of sealed pouches are cut free following their formation. Failing to press and seal the edges properly can result in weakened film pouches, causing such pouches to leak or burst. Even if the delay (i.e., stop) is only for a few milliseconds per cycle, the accumulation of stops over time translates into significantly decreased output and hence decreased revenue for the manufacturer utilizing such an apparatus.
Various devices have been developed to increase the production rate of such film pouches. For example, U.S. Pat. No. 4,726,171 utilizes a vertically moving combination advancement-sealing-separation mechanism that travels between various locations within the apparatus, advancing the film from the film roll, sealing the ends of a pouch, or separating a pouch from the fill, depending upon the particular engagement point. U.S. Pat. Nos. 4,004,397 and 6,178,719 both utilize rotary presses and sealers to minimize delays in the pouch manufacturing process.
Unfortunately, none of these devices are particularly suited for very high-volume production of film pouches. The '171 device does not disclose an apparatus capable of continuous and uninterrupted production, in that the film advancement is temporarily paused while the combination mechanism separates the previous pouch from the film, and resumes only after the mechanism returns to its initial position to receive a subsequent pouch from the sealing heater. Such pause, even if only for a few milliseconds per cycle, results in a noticeably decreased daily output volume for the device. The same is true for the device of U.S. Pat. No. 5,634,324. The '397 and '719 devices require substantial operational floor space, which may not be readily available in some settings. Furthermore, these devices provide a limited amount of time in which to press and seal the pouch edges, increasing the likelihood that the pouch will leak or burst.
It is therefore desirable to provide an apparatus for forming, filling and sealing large volumes of film pouches within a minimal amount of time. It is further desirable that such film pouches be manufactured at a continuous and uninterrupted rate so as to maximize production volume. It is further desirable that the apparatus be capable of simultaneously manufacturing a plurality of film pouches, so as to further maximize production volume. It is further desirable that the apparatus utilizes a minimal amount of operational floor space. It is further desirable that the film pouches produced be not overly susceptible to leakage or breakage.